Patterned thermal liner for protective garments

ABSTRACT

Disclosed are thermal liners for protective garments and protective garments that comprise thermal liners. In one embodiment, a thermal liner comprises an insulation layer comprising a batt of entangled flame resistant fibers, the insulation layer having a three-dimensional pattern that defines a plurality of closed-cell air pockets that are configured to trap air to insulate a wearer of the thermal liner, the insulation layer being shaped and configured for inclusion in the protective garment and for donning by the wearer.

TECHNICAL FIELD

The present disclosure is generally related to protective garments. Moreparticularly, the present disclosure is related to patterned thermalliners that may be used in protective garments.

BACKGROUND

Firefighter garments, generally known as turnout gear, are designed toprevent the firefighter from sustaining injury from the flames and heatto which the firefighter may be exposed on the job. Generally, turnoutgear includes a coat and overalls. Such garments typically comprisethree layers of material that include, from the exterior to theinterior, an outer shell, a moisture barrier, and a thermal liner. Theouter shell layer is typically a woven fabric made from flame resistantfibers and is provided not only to resist flame, but also to protect thewearer against abrasion.

The moisture barrier, which is also flame resistant, is provided toprevent water from the firefighting environment from penetrating andsaturating the garment and, more particularly, the thermal liner. Excessmoisture absorbed by the thermal liner from the environment can encumberthe firefighter to the point of increasing the firefighter's likelihoodof experiencing heat stress.

The thermal liner is also flame resistant and offers the bulk of thethermal protection afforded by the protective garment. Normally, thermalliners include a nonwoven insulation layer composed of flame resistantfibers that is quilted to a lightweight woven facecloth, which typicallyis also constructed of flame resistant fibers.

As is known in the art, it is common for firefighters to perspireprofusely while fighting fires due both to the heat of the environmentand the effort exerted by the firefighter in serving his or her duty.This perspiration is usually absorbed into the thermal liner to keep thefirefighter feeling dry. If a large amount of perspiration is absorbedby the thermal liner, the weight of what is already a relatively heavygarment may be significantly increased. As noted above, this weight cancontribute to heat stress or general fatigue. Accordingly, it isdesirable to provide the required amount of protection with the lightestpossible garment.

SUMMARY

Disclosed are thermal liners for protective garments and protectivegarments that comprise thermal liners. In one embodiment, a thermalliner comprises an insulation layer comprising a batt of entangled flameresistant fibers, the insulation layer having a three-dimensionalpattern that defines a plurality of closed-cell air pockets that areconfigured to trap air to insulate a wearer of the thermal liner, theinsulation layer being shaped and configured for inclusion in theprotective garment and for donning by the wearer.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed garments and methods for making them can be betterunderstood with reference to the following drawings. The components inthe drawings are not necessarily to scale.

FIG. 1 illustrates a partial cut-away view of a protective garment.

FIG. 2 illustrates an exploded perspective view of a portion of thegarment illustrated in FIG. 1.

FIG. 3 illustrates a cross-sectional view of an insulation layermaterial used to construct a thermal liner of the garment shown in FIGS.1 and 2.

FIGS. 4–6 illustrate various embodiments of patterns that may beimparted to the material shown in FIG. 3.

FIG. 7 illustrates apparatus that may be used to fabricate the materialshown in FIG. 3.

DETAILED DESCRIPTION

As noted above, it is desirable to provide the protection required for afirefighter with the lightest possible garment to reduce the burden onthe firefighter. It follows that it is likewise desirable to provide therequired thermal protection with the lightest possible thermal liner.Accordingly, advantageous results can be obtained by using materials forconstruction of the thermal liner that provide the greatest possiblethermal protection per unit weight. In such a case, the thermal liner,and therefore the firefighter garment as a whole, can be made lighterwithout reducing the thermal protection it provides, or can be made morethermally protective without significantly increasing its weight. As isdescribed in greater detail in the following discussions, these goalscan be achieved by providing a patterned thermal liner that comprises aplurality of closed-cell air pockets. When provided, these air pocketstrap air within the thermal liner so as to provide an increasedinsulative effect. Due to the absence of material in these air pockets,improved thermal protection can be provided with less material and,therefore, less weight.

FIG. 1 illustrates an example protective garment 10 that incorporates apatterned thermal liner. More particularly, FIG. 1 illustrates afirefighter turnout coat. Although a turnout coat is illustrated in FIG.1 and explicitly discussed herein, a coat has been identified forpurposes of example only. Accordingly, the present disclosure is notlimited to firefighter turnout coats but instead pertains tosubstantially any firefighter garment or other protective garment thatis to provide thermal protection.

As indicated in both FIGS. 1 and 2, the protective garment 10 has amulti-layer construction that includes an outer shell 12, a moisturebarrier 14, and a thermal liner 16. The outer shell 12 is typicallyconstructed of a flame and abrasion resistant material that comprisesflame resistant fibers made of, for example, aramid (meta-aramid orpara-aramid), polybenzimidazole, polybenzoxazole, melamine, or the like.The outer shell 12 can be treated with a water-resistant finish such asa perfluorohydrocarbon to prevent or reduce water absorption from theoutside environment in which the garment 10 is used. The weight of theouter shell material normally is within the range of about 6 ounces persquare yard (osy) to about 8 osy.

The moisture barrier 14 is constructed of a non-woven or woven flameresistant fabric comprising flame resistant fibers made of, for example,aramid, melamine, or the like. The moisture barrier 14 is typicallylaminated with a water-impermeable layer of material such as, forinstance, a layer of polytetrafluoroethylene or polyurethane. When suchan impermeable layer is provided, it usually is provided on the moisturebarrier 14 so as to face the thermal liner 16. The weight of themoisture barrier material is typically within the range about 4 osy toabout 6 osy.

The thermal liner 16 can, optionally, include both an insulation layer18 and a facecloth layer 20, which are quilted together. In alternativeembodiments, however, the insulation layer 18 alone may be used. As isdescribed in greater detail below, the insulation layer 18 is patternedsuch that it comprises a plurality of closed-cell air pockets (notvisible in FIGS. 1 and 2). When it is used, the facecloth layer 20 canbe constructed of woven material comprising flame resistant fibers madeof, for example, aramid, melamine, flame resistant (FR) rayon,modacrylic, carbon, or the like. The facecloth layer 20 can optionallybe finished with a hydrophilic finish that draws perspiration off of thefirefighter's body, if desired. The weight of the facecloth layermaterial is normally in the range of about 1 osy to about 6 osy.

The insulation layer 18 comprises a nonwoven material (i.e., batt) thatcomprises a plurality of flame resistant fibers. By way of example,these fibers are made of aramid, melamine, FR rayon, modacrylic, carbon,or the like. The insulation layer material typically has a weight in therange of about 0.75 osy to about 8 osy. In a presently preferredconfiguration, the insulation layer material has a weight in the rangeof about 1.5 osy to about 2.7 osy. Notably, the weight of the insulationlayer material used may depend upon how many individual fabric layersthe insulation layer 18 comprises. For instance, a single layer ofmaterial having a weight of about 2 osy may be substituted with twolayers of material having individual weights of about 1 osy or less, ifdesired. Irrespective of its weight, the material used to form theinsulation layer 18 comprises a three-dimensional pattern (not visiblein FIGS. 1 and 2) that forms the aforementioned closed-cell air pockets.

FIG. 3 illustrates an example insulation layer material 22 incross-section. As indicated in this figure, a pattern 24 is imposed uponthe insulation layer material 22 that creates a plurality of closed-cellair pockets 26 on one side of the material that are used to trap airbetween the insulation layer 18 and the facecloth layer 20, or thewearer's body if no facecloth layer is provided. These air pockets 26are designated as “closed-cell” air pockets in that each pocket isseparated from adjacent pockets by boundary walls 28 that define thepocket such that air from one air pocket cannot easily mix with air fromone or more adjacent air pockets. This feature impedes heat transfer andtherefore increases the insulative effect of the insulation layer 18. Asshown in FIG. 3, each air pocket 26 has a transverse dimension, t, and adepth dimension, d. By way of example, the transverse dimension t iswithin the range of about 1/16 inches to about ½ inches and the depthdimension d is within the range of about ⅛ inches to about 5/16 inches.

FIGS. 4–6 illustrate various different geometric patterns that can beimposed upon the insulation layer material 22 to form the closed-cellair pockets. In particular, FIG. 4 illustrates a honeycomb pattern 26that comprises a plurality of honeycomb cells 28, wherein each cellforms an air pocket (on the reverse side of the material). As shown inthis figure, the cells 28 are closely-packed such that a maximum numberof closed-cell air pockets are provided. FIG. 5 illustrates a circularpattern 30 that comprises a plurality of circular cells 32. Finally,FIG. 6 illustrates a triangular pattern 34 that comprises a plurality oftriangular cells 36. Although specific patterns are identified withreference to FIGS. 4–6, substantially any pattern that comprises aplurality of relatively small, closely-packed cells may be used.Irrespective of the shapes of the cells formed by the pattern imposedupon the insulation layer material 22, their dimensions preferably arerelatively small in size. By way of example, each cell can havetransverse (length and width) dimensions approximately equal to about ¼inch or smaller. In other words, each cell can cover an area of theinsulation layer material 22 of approximately 1/16 square inches orsmaller.

The insulation layer material 22 can be fabricated using a variety ofdifferent methods. In one suitable fabrication method, ahydroentanglement process is used which both entangles the fibers of thematerial 22 and forms the desired pattern on the material. An example ofsuch a method is described in detail in published internationalapplication no. WO 02/47907, which is hereby incorporated by referenceinto the present disclosure in its entirety. Another example of such amethod is described in published international application no. WO02/058006, which is also hereby incorporated by reference into thepresent disclosure in its entirety.

FIG. 7 illustrates an apparatus 38 used in the aforementioned publishedinternational applications for practicing the preferredhydroentanglement process used to form the patterned insulation layermaterial 22. In this process, a fibrous matrix preferably comprisingstaple length fibers is first formed. Alternatively, however, differenttypes of fibers, or fiber blends, can be employed. The fibers of thematrix may be selected from fibers of homogeneous or mixed fiberlengths. Suitable fibers include, for example, aramid fibers, melaminefibers, FR rayon fibers, modacrylic fibers, and carbon fibers. Staplelengths are preferably selected in the range of about 0.25 inch to about4 inches, with the range of about 1 to 2 inches being preferred. Thefiber denier is selected in the range of about 0.08 denier to about 15denier, with the range of about 1 to 6 denier being preferred.

The fibrous matrix is preferably carded and air-laid or cross-lapped toform a precursor web, designated P. Alternatively, however, a scrim canbe interposed in the formation of the precursor web. The purpose of thescrim, when provided, is to reduce the extensibility of the resultantthree-dimensional patterned (“imaged”) nonwoven material, thus reducingthe possibility of three-dimensional pattern (“image”) distortion andfurther enhancing fabric durability. Suitable scrims includeunidirectional monofilament, bi-directional monofilament, expandedfilms, and thermoplastic spunbond.

A binder material can also be incorporated either as a fusible fiber inthe formation of the precursor web P or as a liquid fiber adhesiveapplied after imaged fabric formation. When used, the binder materialimproves the durability of the resultant imaged nonwoven fabric duringapplication of harsh or abrasive surface treatments.

With further reference to FIG. 7, the precursor web P is fed through apre-wetting station 40 using a suitable conveyance mechanism such as abelt 42. At this station 40, high pressure water is applied to the web Pusing an entangling manifold 44 such that the fibers of the web areentangled with each other. By way of example, jets of water can beapplied with 120 micron orifices spaced at 42.3 per inch with themanifolds successively operated at three strips each at 100, 300, 800,and 800 pounds per square inch (psi) at a line speed of 60 feet perminute. In another example, three orifice strips each including 120micron orifices spaced at 42.3 per inch and operated at 100, 300, and600 psi with a line speed of 45 feet per minute may be used. In analternative method, the web P may be needlepunched using aneedlepunching machine instead of being hydroentangled using the station40.

Once passing through the pre-wetting station 40, the entangled web isapplied to a drum 46, which comprises a plurality of three-dimensionalimage elements that are used to impart the selected pattern to the weband, therefore, the resultant material. These image elements compriseopenings or depressions that are used to form the various cells of theinsulation layer material 22. When openings are provided, the openingsact as drainage openings in the surface of the drum 46 for the highpressure water streams that are ejected from entangling manifolds 48positioned around the periphery of the drum. These openings can, forexample, have diameters in the range of about 0.1 to 0.2 inches. Thestreams or jets cause the fibers of the web to further entangle and formthe cells by conforming to the shape of the drum 46. If openings areused, the web density, jet pressure, and opening sizes are selected suchthat fibers are urged into the openings but do not separate to formopenings in the web. Instead, three-dimensional cells are formed at eachopening (or depression) so as to form the desired pattern.

By way of example, three entangling manifolds 48 are operated at 2800psi at a line speed of 60 feet per minute or 45 feet per minute. Oncepatterned on the drum 46, the now-formed insulation layer material 22 isdewatered at a vacuum dewatering station 50, dried over drying cans 52,and then wound by a winder 54.

The advantageous results that are obtainable when a pattern is imposedupon an insulation layer material 22, and therefore the thermal liner16, can be appreciated from Table I. This table compares the thermalprotective performance (TPP) of two different garment types, eachincluding a layer of outer shell material, a layer of water barriermaterial, and a layer of thermal liner material. Garment Type #1comprised a woven 7.5 osy outer shell made of 60% para-aramid and 40%PBI; a Crosstech 2C® moisture barrier supplied by W. L. Gore; two layersof a patterned spunlace insulation layer with each layer weighing 2.5osy and made up of 50% Basofil fibers supplied by Basofil Fibers LLC,25% meta-aramid, and 25% para-aramid; and a woven face cloth of 100%meta-aramid weighing 3.7 osy.

Garment Type #2 comprised a woven 7.5 osy outer shell made of 60%para-aramid and 40% PBO; a Crosstech 2C® moisture barrier; two layers ofa patterned spunlace insulation layer with each layer weighing 2.5 osyand made of 50% Basofil, 25% meta-aramid, and 25% para-aramid; and awoven face cloth of 100% meta-aramid weighing 3.7 osy.

TABLE I Avg. Composite Wt % Change Insulation Layer TPP % Inc. (oz/yd)TPP/oz TPP/oz GARMENT TYPE #1 Before Wash 2 layer Control 38.6 n/a 9.24.20 n/a 2 layer Small 43.1 11.7% 8.7 4.94 17.6% Honeycomb 2 layer Large42.9 11.1% 8.6 4.97 18.4% Honeycomb After 5× Wash 2 layer Control 48.6n/a 8.7 5.61 n/a 2 layer Small 49.2  1.2% 8.6 5.72  2.0% Honeycomb 2layer Large 50.9  4.7% 8.8 5.82 3.7% only 2 Honeycomb samples in TPPGARMENT TYPE #2 Before Wash 2 layer Control 36.8 n/a 9.2 4.00 n/a 2layer Small 41.1 11.7% 9.0 4.55 13.7% Honeycomb 2 layer Large 39.7  7.9%9.0 4.39  9.9% Honeycomb After 5× Wash 2 layer Control 45.7 n/a 9.0 5.06n/a 2 layer Small 47.3  3.5% 8.8 5.35  5.8% Honeycomb 2 layer Large 45.9  0% 8.4 5.44  7.6% Honeycomb

Testing was conducted both before and after laundering as to eachgarment type. More particularly, testing was conducted on threedifferent versions of each garment type: (1) a version incorporating twolayers of plain insulation layer material (i.e., the control), (2) aversion incorporating two layers of patterned insulation layer materialhaving small honeycomb cells, and (3) a version incorporating two layersof patterned insulation layer material having large honeycomb cells. Thesmall honeycomb cells had transverse dimensions (from one edge to theopposite, parallel edge) of approximately ⅛ inches, while the largehoneycomb cells had transverse dimensions (from one edge to theopposite, parallel edge) of approximately ¼ inches.

In that the weights of the patterned insulation layer material were lessthan the plain insulation material of the “control” garments, thecontrol version of each garment type was heavier (in terms of compositeweight) than the versions that incorporated patterned insulationmaterial. Despite this fact, however, the TPP values were generallyhigher for the garment versions that incorporated the patternedinsulation material. For instance, the TPP values for the versions ofGarment Type #1 using patterned insulation material exhibited TPP valuesapproximately 11% to 12% greater than the version of Garment Type #1using the plain insulation material. When the differences in weight aretaken into account, however, the percentage increase is much larger. Forinstance, the percentage increase in TPP values per ounce for theversions of Garment Type #1 using patterned insulation material wereapproximately 18% greater than the version of Garment Type #1 using theplain insulation material.

From the above, it can be appreciated that greater thermal protectionper unit weight can be provided when thermal liners incorporatingpatterned insulation layer material are used. Accordingly, the samethermal protection provided by conventional garments can be provided bya significantly lighter garment, or increased thermal protection can beprovided by a garment having the same weight as a conventional garment.

1. A thermal liner for use in a protective garment, the linercomprising: an insulation layer comprising a batt of entangled flameresistant fibers, the batt having a three-dimensional pattern thatdefines a plurality of closed-cell air pockets that are configured totrap air to insulate a wearer of the thermal liner, the insulation layerbeing shaped and configured for inclusion in the protective garment andfor donning by the wearer.
 2. The thermal liner of claim 1, wherein thebatt comprises at least one of aramid, melamine, FR rayon, modacrylic,and carbon fibers.
 3. The thermal liner of claim 1, wherein theclosed-cell air pockets are formed on an inner side of the insulationlayer adapted to face the wearer.
 4. The thermal liner of claim 1,wherein the closed-cell air pockets are defined by boundary walls. 5.The thermal liner of claim 1, wherein the closed-cell air pocketscomprise repeated geometric shapes.
 6. The thermal liner of claim 5,wherein the repeated geometric shapes comprise at least one ofhoneycombs, circles, and triangles.
 7. The thermal liner of claim 1,wherein the closed-cell air pockets have transverse dimensions withinthe range of about 1/16 inches to about ½ inches and depth dimensionswithin the range of about ⅛ inches to about 5/16 inches.
 8. The thermalliner of claim 1, wherein the insulation layer has a weight in the rangeof about 0.75 ounces per square yard to about 8 ounces per square yard.9. The thermal liner of claim 1, wherein the insulation layer has aweight in the range of about 1.5 ounces per square yard to about 2.7ounces per square yard.
 10. The thermal liner of claim 1, comprisingmultiple insulation layers, each insulation layer comprising a batt ofentangled flame resistant fibers and having a three-dimensional patternthat defines a plurality of closed-cell air pockets that are configuredto trap air to insulate the wearer of the thermal liner.
 11. The thermalliner of claim 1, further comprising a facecloth layer that is attachedto the insulation layer, the facecloth layer comprising a plurality offlame resistant fibers.
 12. The thermal liner of claim 11, wherein thefacecloth layer is attached to an inner side of the insulation layersuch that the closed-cell air pockets of the insulation layer face thefacecloth layer.
 13. The thermal liner of claim 11, wherein thefacecloth layer comprises at least one of aramid, melamine, FR rayon,modacrylic, and carbon fibers.
 14. The thermal liner of claim 11,wherein the facecloth layer comprises a hydrophilic finish.
 15. Athermal liner for use in a protective garment, the liner comprising: aninsulation layer comprising a batt of entangled flame resistant fibers,the batt having a three-dimensional geometric pattern provided on aninner side of the insulation layer that forms a plurality of closed-cellair pockets that are defined by boundary walls and that are configuredto trap air to insulate a wearer of the thermal liner; and a faceclothlayer that is attached to the inner side of the insulation layer, thefacecloth layer comprising a plurality of flame resistant fibers;wherein the thermal liner is shaped and configured for inclusion in theprotective garment and for donning by the wearer.
 16. The thermal linerof claim 15, wherein the batt comprises at least one of aramid,melamine, FR rayon, modacrylic, and carbon fibers.
 17. The thermal linerof claim 15, wherein the closed-cell air pockets have geometric shapesthat comprise at least one of honeycombs, circles, and triangles. 18.The thermal liner of claim 15, wherein the closed-cell air pockets havetransverse dimensions within the range of about 1/16 inches to about ½inches and depth dimensions within the range of about ⅛ inches to about5/16 inches.
 19. The thermal liner of claim 15, wherein the insulationlayer has a weight in the range of about 0.75 ounces per square yard toabout 8 ounces per square yard.
 20. The thermal liner of claim 15,wherein the insulation layer has a weight in the range of about 1.5ounces per square yard to about 2.7 ounces per square yard.
 21. Thethermal liner of claim 15, comprising multiple insulation layers, eachinsulation layer comprising a batt of entangled flame resistant fibersand a three-dimensional pattern that defines a plurality of closed-cellair pockets that are configured to trap air to insulate the wearer ofthe thermal liner.
 22. The thermal liner of claim 15, wherein thefacecloth layer comprises at least one of aramid, melamine, FR rayon,modacrylic, and carbon fibers.
 23. The thermal liner of claim 15,wherein the facecloth layer comprises a hydrophilic finish.
 24. Aprotective garment, comprising: an outer shell formed of a flame andabrasion resistant material; a moisture barrier formed of a flameresistant material; and a thermal liner including an insulation layercomprising a batt of entangled flame resistant fibers, the batt having athree-dimensional pattern provided on an inner side of the insulationlayer that forms a plurality of closed-cell air pockets that areconfigured to trap air to insulate a wearer of the protective garment.25. The protective garment of claim 24, wherein the insulation layerbatt comprises at least one of aramid, melamine, FR rayon, modacrylic,and carbon fibers.
 26. The protective garment of claim 24, wherein theclosed-cell air pockets of the insulation layer comprise repeatedgeometric shapes.
 27. The protective garment of claim 26, wherein therepeated geometric shapes comprise at least one of honeycombs, circles,and triangles.
 28. The protective garment of claim 24, wherein theclosed-cell air pockets of the insulation layer have transversedimensions within the range of about 1/16 inches to about ½ inches anddepth dimensions within the range of about ⅛ inches to about 5/16inches.29. The protective garment of claim 24, wherein the insulation layer hasa weight in the range of about 0.75 ounces per square yard to about 8ounces per square yard.
 30. The protective garment of claim 24, whereinthe insulation layer has a weight in the range of about 1.5 ounces persquare yard to about 2.7 ounces per square yard.
 31. The protectivegarment of claim 24, wherein the insulation layer comprises a faceclothlayer that is attached to the inner side of the insulation layer, thefacecloth layer comprising a plurality of flame resistant fibers. 32.The protective garment of claim 31, wherein the facecloth layercomprises at least one of aramid, melamine, FR rayon, modacrylic, andcarbon fibers.
 33. A thermal liner comprising: an insulation layercomprising a batt of entangled flame resistant fibers, the batt having athree-dimensional pattern that is physically imprinted into the batt,the three-dimensional pattern defining a plurality of closed-cell airpockets that are configured to trap air to insulate a wearer of thethermal liner.
 34. The thermal liner of claim 33, wherein thethree-dimensional pattern is physically imprinted into the batt througha hydroentanglement process.
 35. The thermal liner of claim 33, whereinthe batt comprises one or more of aramid, melamine, FR rayon,modacrylic, and carbon fibers.
 36. The thermal liner of claim 33,wherein the closed-cell air pockets are defined by boundary walls thatseparate each air pocket from adjacent air pockets.
 37. The thermalliner of claim 33, wherein the closed-cell air pockets comprise repeatedgeometric shapes.
 38. The thermal liner of claim 37, wherein therepeated geometric shapes comprise one or more of honeycombs, circles,and triangles.
 39. The thermal liner of claim 33, wherein theclosed-cell air pockets have transverse dimensions within the range ofabout 1/16 inches to about ½ inches and depth dimensions within therange of about ⅛ inches to about 5/16 inches.
 40. The thermal liner ofclaim 33, wherein the insulation layer has a weight in the range ofabout 1.5 ounces per square yard to about 2.7 ounces per square yard.41. The thermal liner of claim 33, further comprising a facecloth layerthat is attached to the insulation layer, the facecloth layer comprisinga plurality of flame resistant fibers.
 42. The thermal liner of claim33, wherein the facecloth layer is attached to an inner side of theinsulation layer such that the closed-cell air pockets of the insulationlayer face the facecloth layer.
 43. The thermal liner of claim 42,wherein the facecloth layer comprises a hydrophilic finish.